Amounts of UDP traffic below some limit are not transmitted with aviocat

Description

Summary of the bug:
Amounts of UDP traffic below some limit are not transmitted with aviocat. Haven't determined yet whether that's just aviocat, or UDP protocol implementation failure.
The problem must be on receiving side (because traffic is seen in sniffer, and because GStreamer udpsrc catches it).
Transmitting and reading continuous media stream by same UDP address works (both unicast and multicast).